Output error message when a command is not found. Closes #778

Plugins with commands will need to implement a catch-all command that exits with the `DOKKU_NOT_IMPLEMENTED_EXIT`` code (10). This signals to dokku that a given plugin has indeed not executed anything for a plugin (which may not always be the case).

Using plugins that do not implement this pattern will result in those plugins silencing the error message.

plugins/00_dokku-standard/commands

@@ -73,4 +73,8 @@ case "$1" in
 EOF
     ;;
 
+  *)
+    exit $DOKKU_NOT_IMPLEMENTED_EXIT
+    ;;
+
 esac

plugins/apps/commands

@@ -72,4 +72,8 @@ case "$1" in
 EOF
     ;;
 
+  *)
+    exit $DOKKU_NOT_IMPLEMENTED_EXIT
+    ;;
+
 esac

plugins/backup/commands

@@ -92,4 +92,8 @@ case "$1" in
 EOF
     ;;
 
+  *)
+    exit $DOKKU_NOT_IMPLEMENTED_EXIT
+    ;;
+
 esac

plugins/config/commands

@@ -184,4 +184,8 @@ ${var}"
 EOF
     ;;
 
+  *)
+    exit $DOKKU_NOT_IMPLEMENTED_EXIT
+    ;;
+
 esac

plugins/git/commands

@@ -58,4 +58,8 @@ EOF
     cat
     ;;
 
+  *)
+    exit $DOKKU_NOT_IMPLEMENTED_EXIT
+    ;;
+
 esac

plugins/nginx-vhosts/commands

@@ -41,4 +41,8 @@ case "$1" in
 EOF
     ;;
 
+  *)
+    exit $DOKKU_NOT_IMPLEMENTED_EXIT
+    ;;
+
 esac